1. Field of the Invention
The invention relates to the technology of alcohol recovery from aqueous fermentate and provides for an energy efficient separation of the alcoholic component thereof. The process operates under reduced pressure to enrich the final product to yield up to 195 proof (97.5 volume percent) ethyl alcohol.
2. Disclosure Statement
U.S. Pat. No. 2,389,789, issued Nov. 27, 1945, to A. Latham, Jr., discloses a distillation method utilizing the sensible heat derived from an internal combustion engine for preheating fresh solution fed to the vaporization zone of an evaporator. U.S. Pat. No. 2,643,974, issued June 30, 1953, to A. M. Impagliazzo, discloses a device for using waste heat from either the lubricating oil or water jacket of a diesel engine or any other heat engine having a recirculating coolant or lubricant, and uses the heat for evaporation of water. A. Plaek, in U.S. Pat. No. 2,400,370, issued May 14, 1946, discloses separation of alcoholic components from a fermented mash including ethyl alcohol and water, where waste heat is recovered with use plural heat exchangers. L. T. Hendrix, in U.S. Pat. No. 3,388,046, issued June 11, 1968, discloses heat recovery in distillation apparatus.
Vapor recompression is disclosed in the publication Unit Operations of Chemical Engineering, Third Edition, McCabe and Smith, McGraw-Hill, 1976. A heat pump distillation system is disclosed in Chemical Engineering Progress, November, 1977, page 79. Vapor-liquid equilibrium data for the ethanol-water system are disclosed in Distillation Equilibrium Data, J. C. Chu, Reinhold Publishing Corporation, 1950, page 90.
Other patents relating to the field of the invention include the following:
U.S. Pat. No. 2,276,089--Mar. 10, 1942--Ragatz PA1 U.S. Pat. No. 3,455,791--July 15, 1969--Nash et al.